Fix compiler and IDE tests on Experimental/RequiresOptIn

See cdbabf224f, e009c7064e

idea/testData/quickfix/experimental/basicUseExperimental.kt.after

@@ -1,4 +1,4 @@
-// "Add '@UseExperimental(MyExperimentalAPI::class)' annotation to 'bar'" "true"
+// "Add '@OptIn(MyExperimentalAPI::class)' annotation to 'bar'" "true"
 // COMPILER_ARGUMENTS: -Xuse-experimental=kotlin.Experimental
 // WITH_RUNTIME
 
@@ -14,8 +14,8 @@ class Some {
 }
 
 class Bar {
-    @UseExperimental(MyExperimentalAPI::class)
+    @OptIn(MyExperimentalAPI::class)
     fun bar() {
         Some().foo()
     }
-}
+}